HDC与RPC加固RC柱轴心受压性能试验研究

EXPERIMENTAL INVESTIGATION ON AXIAL COMPRESSION BEHAVIOR OF RC COLUMNS STRENGTHENED WITH HDC AND RPC JACKETS

为研究高延性混凝土(HDC)和活性粉末混凝土(RPC)围套加固钢筋混凝土(RC)柱的轴心抗压性能,设计制作了8个RC方柱,其中4个采用HDC加固、3个采用RPC加固、1个未加固作为对比试件,通过轴心受压试验,研究了加固层材料、加固层受压方式和加固层是否配置钢筋网对试验结果的影响,分析了各试件的破坏形态、荷载-位移曲线和应变发展规律。试验结果表明:加固柱的破坏形态得到改善;配置钢筋网的加固层整体性较强;加固层与混凝土界面具有可靠的粘结强度,两者变形协调;加固试件的承载力和变形能力均有所提高;加固层直接受压的加固试件承载力提高幅度较大。通过分析加固层的工作机理,考虑了加固层应力滞后的影响,给出加固试件的受压承载力计算公式,其计算结果与试验结果较为吻合。

In order to study the axial compressive behavior of reinforced concrete(RC)columns strengthened with high ductile concrete(HDC)and reactive powder concrete(RPC)jackets.Eight RC square columns were prepared;four of them were jacketed with HDC,three with RPC and one control specimen.Axial compression tests were carried out to investigate the influence of the material types,the loaded ways and the reinforcement arrangements of the jackets on test results.The failure modes,bearing capacity,load-displacement curves and strain development of specimens are analyzed.Test results show that the failure modes of strengthened columns have been improved.The jackets reinforced with steel mesh exhibit good integrity.The interface between jacket and concrete has reliable bond strength.Thusly,the bearing capacity and deformation capacity of all strengthened specimens have been improved.The bearing capacity of strengthened specimens is increased greatly,whose jackets are directly loaded.Based on the analysis of the strengthening mechanism of jackets,the formulas for calculating the bearing capacity of the strengthened specimens is developed,in which the stress lag of jackets is considered.And the calculating results are in a good agreement with the experimental results.